The present invention relates to a multi-direction operating switch for use in an electronic device such as an air-conditioning control device for an automobile and the like. The invention also relates to an electronic device using the same.
FIG. 6 is a front view of an air-conditioning control device equipped with a typical operating switch of the prior art. In the past, an operating switch of this kind had a push-to-operate type configuration, and it was provided with operating buttons 17 for a number of pushbutton switches corresponding to a plurality of functions if it is adapted for switching a plurality of functions such as a blowing-out mode for delivering air into an interior space, and so on.
In recent years, multi-directional operating switches of a type that switches a plurality of functions with manipulation of one operating button instead of the operating buttons 17 of the plurality of pushbutton switches have come into use. With reference to FIG. 7 and FIG. 8, a conventional multi-directional operating switch of this kind will be described hereinafter.
FIG. 7 is a sectioned side view of a multi-directional operating switch of the prior art, and FIG. 8 is an exploded perspective view of the same. In the Figures, there is a substrate 1 made of insulation resin having an open top. The substrate 1 is provided on its bottom center surface with an upwardly projecting boss 1B having a hole-like receptacle 1A at an upper end of it. The receptacle 1A houses a supporting rod 3, which is biased upwardly by a coil spring 2, and serves as an inner support with a semispherical top end. There are two screw bosses 1C located adjacent to the boss 1B.
Six pushbutton switches 5 defining switch units are disposed in a circular configuration on an upper surface of a wiring substrate 4 made of insulation board. A center through hole 4A is inserted around the boss 1B of the substrate 1, and the wiring substrate 4 is secured to the screw bosses 1C of the substrate 1 with two screws 6. Lead wires 7 connected with the wiring substrate 4 are drawn out through a slit 1D in an outer periphery of the substrate 1, and connected electrically to an electronic circuit of an automobile (not shown in the figures).
A bowl-shaped tilting body 8 is disposed above the wiring substrate 4. The tilting body 8 is provided with a concavity 8A having a spherical upper end under a center portion of a bowl-shaped section 8D of the tilting body 8. Depressing bosses 8C, each located on a lower surface of each of six fringe arms 8B extending radially outward from a bottom edge of the bowl-shaped section 8D are in contact with their respective upper surfaces of the pushbuttons 5C of the pushbutton switches 5. There is a manipulation shaft 8E with a stepped diameter having a large diameter at its lower portion, and projecting upwardly from an upper part of the bowl-shaped section 8D.
A box-shaped case 9 having an open bottom is mounted over the substrate 1 to cover the opening on top of it. The case 9 has an opening 9A in its upper center surface in a position concentric with the supporting rod 3, which serves as an inner support of the substrate 1. There is a contact face 9B provided under a periphery of the opening 9A, the contact face 9B being in contact with an outer surface of the bowl-shaped section 8D of the tilting body 8, and serving as an outer support with its inwardly concaved semispherical shape. There are guide posts 9C projecting downward from the periphery of the contact face 9B in a such positional arrangement as to provide a predetermined space with respect to perimeters of the fringe arms 8B so as to prevent the tilting body 8 from turning about the manipulation shaft 8E.
A manipulation knob 10 has a disk-shaped manipulation surface 10A, which covers the opening 9A in the case 9, and a connection post 10B on a lower side, with which the manipulation knob 10 is connected and secured to the manipulation shaft 8E of the tilting body 8. With the foregoing structure, the manipulation knob 10 can be tiltably manipulated toward any of a plurality of directions shown by an indicator 9D, or a marking printed on the case 9.
In the multi-directional operating switch of the above-described structure, when the manipulation surface 10A of the manipulation knob 10 is tilted toward a given direction, a depressing boss 8C under one of the fringe arms 8B of the tilting body 8 corresponding to the given direction depresses a pushbutton 5C of the respective pushbutton switch 5, and opens or closes the pushbutton switch 5, while the upper end of the supporting rod 3 functions as the fulcrum, since the tilting body 8 is supported in a tiltable manner between the contact face 9B serving as the outer support provided under a periphery of the opening 9A of the case 9 and the supporting rod 3 serving as the inner support placed in the substrate 1.
The multi-directional operating switch of the prior art is so designed that by tilting the manipulation shaft 8E of the tilting body 8 correctly toward a direction where a predetermined pushbutton switch 5 is positioned, the depressing boss 8C corresponding to that direction shifts downward, and turns the predetermined pushbutton switch 5 into an ON state. During this manipulation, other depressing bosses next to that depressing boss 8C also shift downward slightly, but other pushbutton switches are not normally turned into ON state.
There has been a problem, however, that another pushbutton switch is also depressed unintentionally into its ON state at, the same time, when the manipulation shaft 8E is being tilted to the direction where a predetermined pushbutton switch 5 is positioned, if it is tilted inadvertently in a slightly deviated direction toward the another pushbutton switch next to the predetermined switch 5.
The present invention was made in consideration of the above problem of the prior art, and it aims at providing a multi-directional operating switch of excellent operability, as it avoids adjoining pushbutton switch from being depressed and turned into an ON state unintentionally even if a manipulation shaft is tilted inadvertently in a slightly deviated direction toward the adjoining pushbutton switch, and providing an electronic device using this multidirectional operating switch.
The multi multi-directional operating switch of the present invention comprises:
(a) a box-shaped case having an opening in an upper surface and an outer support provided under an outer periphery of the opening;
(b) a substrate disposed under the case and provided with an inner support in a position concentric with the opening;
(c) a tilting body provided with a bowl-shaped section supported tiltably between the inner support and the outer support, and a manipulation shaft projecting upwardly from the bowl-shaped section to the outside through the above opening; and
(d) a plurality of switch units disposed in a circular configuration, and turned on and off by a depressing boss provided on a bottom fringe of the bowl-shaped section.
Further, an inner peripheral wall of the opening is provided with (1) a plurality of recessed grooves elongated in an axial direction, in positions corresponding with respective directions where the plurality of switch units are disposed, and (2) heaped-up portions projecting inwardly and elongated along the axial direction between the plurality of recessed grooves.
Furthermore, an outer periphery of the manipulation shaft is provided with (1) a plurality of raised protuberances for engaging with corresponding one of the plurality of recessed grooves in response to a tilting movement of the manipulation shaft, and (2) clearance slots, each provided on both sides of each of the plurality of protuberances for clearing the heaped-up portions during the tilting movement.
The electronic device of this invention comprises at least one of the multi-directional operating switches and a frame for mounting the multi-directional operating switches, thereby making it possible for any of the multi multi-directional switches operative to select multiple functions.